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2012-06-14tracing: Register the ftrace internal events during early bootSteven Rostedt
All trace events including ftrace internel events (like trace_printk and function tracing), register functions that describe how to print their output. The events may be recorded as soon as the ring buffer is allocated, but they are just raw binary in the buffer. The mapping of event ids to how to print them are held within a structure that is registered on system boot. If a crash happens in boot up before these functions are registered then their output (via ftrace_dump_on_oops) will be useless: Dumping ftrace buffer: --------------------------------- <...>-1 0.... 319705us : Unknown type 6 --------------------------------- This can be quite frustrating for a kernel developer trying to see what is going wrong. There's no reason to register them so late in the boot up process. They can be registered by early_initcall(). Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-06-14ftrace: Remove a superfluous checkBorislav Petkov
register_ftrace_function() checks ftrace_disabled and calls __register_ftrace_function which does it again. Drop the first check and add the unlikely hint to the second one. Also, drop the label as John correctly notices. No functional change. Link: http://lkml.kernel.org/r/20120329171140.GE6409@aftab Cc: Borislav Petkov <bp@amd64.org> Cc: John Kacur <jkacur@redhat.com> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-06-13splice: fix racy pipe->buffers usesEric Dumazet
Dave Jones reported a kernel BUG at mm/slub.c:3474! triggered by splice_shrink_spd() called from vmsplice_to_pipe() commit 35f3d14dbbc5 (pipe: add support for shrinking and growing pipes) added capability to adjust pipe->buffers. Problem is some paths don't hold pipe mutex and assume pipe->buffers doesn't change for their duration. Fix this by adding nr_pages_max field in struct splice_pipe_desc, and use it in place of pipe->buffers where appropriate. splice_shrink_spd() loses its struct pipe_inode_info argument. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Tom Herbert <therbert@google.com> Cc: stable <stable@vger.kernel.org> # 2.6.35 Tested-by: Dave Jones <davej@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-06-06tracing: Have tracing_off() actually turn tracing offSteven Rostedt
A recent update to have tracing_on/off() only affect the ftrace ring buffers instead of all ring buffers had a cut and paste error. The tracing_off() did the exact same thing as tracing_on() and would not actually turn off tracing. Unfortunately, tracing_off() is more important to be working than tracing_on() as this is a key development tool, as it lets the developer turn off tracing as soon as a problem is discovered. It is also used by panic and oops code. This bug also breaks the 'echo func:traceoff > set_ftrace_filter' Cc: <stable@vger.kernel.org> # 3.4 Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-30Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar. * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits) perf ui browser: Stop using 'self' perf annotate browser: Read perf config file for settings perf config: Allow '_' in config file variable names perf annotate browser: Make feature toggles global perf annotate browser: The idx_asm field should be used in asm only view perf tools: Convert critical messages to ui__error() perf ui: Make --stdio default when TUI is not supported tools lib traceevent: Silence compiler warning on 32bit build perf record: Fix branch_stack type in perf_record_opts perf tools: Reconstruct event with modifiers from perf_event_attr perf top: Fix counter name fixup when fallbacking to cpu-clock perf tools: fix thread_map__new_by_pid_str() memory leak in error path perf tools: Do not use _FORTIFY_SOURCE when DEBUG=1 is specified tools lib traceevent: Fix signature of create_arg_item() tools lib traceevent: Use proper function parameter type tools lib traceevent: Fix freeing arg on process_dynamic_array() tools lib traceevent: Fix a possibly wrong memory dereference tools lib traceevent: Fix a possible memory leak tools lib traceevent: Allow expressions in __print_symbolic() fields perf evlist: Explicititely initialize input_name ...
2012-05-24Merge branch 'perf-uprobes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull user-space probe instrumentation from Ingo Molnar: "The uprobes code originates from SystemTap and has been used for years in Fedora and RHEL kernels. This version is much rewritten, reviews from PeterZ, Oleg and myself shaped the end result. This tree includes uprobes support in 'perf probe' - but SystemTap (and other tools) can take advantage of user probe points as well. Sample usage of uprobes via perf, for example to profile malloc() calls without modifying user-space binaries. First boot a new kernel with CONFIG_UPROBE_EVENT=y enabled. If you don't know which function you want to probe you can pick one from 'perf top' or can get a list all functions that can be probed within libc (binaries can be specified as well): $ perf probe -F -x /lib/libc.so.6 To probe libc's malloc(): $ perf probe -x /lib64/libc.so.6 malloc Added new event: probe_libc:malloc (on 0x7eac0) You can now use it in all perf tools, such as: perf record -e probe_libc:malloc -aR sleep 1 Make use of it to create a call graph (as the flat profile is going to look very boring): $ perf record -e probe_libc:malloc -gR make [ perf record: Woken up 173 times to write data ] [ perf record: Captured and wrote 44.190 MB perf.data (~1930712 $ perf report | less 32.03% git libc-2.15.so [.] malloc | --- malloc 29.49% cc1 libc-2.15.so [.] malloc | --- malloc | |--0.95%-- 0x208eb1000000000 | |--0.63%-- htab_traverse_noresize 11.04% as libc-2.15.so [.] malloc | --- malloc | 7.15% ld libc-2.15.so [.] malloc | --- malloc | 5.07% sh libc-2.15.so [.] malloc | --- malloc | 4.99% python-config libc-2.15.so [.] malloc | --- malloc | 4.54% make libc-2.15.so [.] malloc | --- malloc | |--7.34%-- glob | | | |--93.18%-- 0x41588f | | | --6.82%-- glob | 0x41588f ... Or: $ perf report -g flat | less # Overhead Command Shared Object Symbol # ........ ............. ............. .......... # 32.03% git libc-2.15.so [.] malloc 27.19% malloc 29.49% cc1 libc-2.15.so [.] malloc 24.77% malloc 11.04% as libc-2.15.so [.] malloc 11.02% malloc 7.15% ld libc-2.15.so [.] malloc 6.57% malloc ... The core uprobes design is fairly straightforward: uprobes probe points register themselves at (inode:offset) addresses of libraries/binaries, after which all existing (or new) vmas that map that address will have a software breakpoint injected at that address. vmas are COW-ed to preserve original content. The probe points are kept in an rbtree. If user-space executes the probed inode:offset instruction address then an event is generated which can be recovered from the regular perf event channels and mmap-ed ring-buffer. Multiple probes at the same address are supported, they create a dynamic callback list of event consumers. The basic model is further complicated by the XOL speedup: the original instruction that is probed is copied (in an architecture specific fashion) and executed out of line when the probe triggers. The XOL area is a single vma per process, with a fixed number of entries (which limits probe execution parallelism). The API: uprobes are installed/removed via /sys/kernel/debug/tracing/uprobe_events, the API is integrated to align with the kprobes interface as much as possible, but is separate to it. Injecting a probe point is privileged operation, which can be relaxed by setting perf_paranoid to -1. You can use multiple probes as well and mix them with kprobes and regular PMU events or tracepoints, when instrumenting a task." Fix up trivial conflicts in mm/memory.c due to previous cleanup of unmap_single_vma(). * 'perf-uprobes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits) perf probe: Detect probe target when m/x options are absent perf probe: Provide perf interface for uprobes tracing: Fix kconfig warning due to a typo tracing: Provide trace events interface for uprobes tracing: Extract out common code for kprobes/uprobes trace events tracing: Modify is_delete, is_return from int to bool uprobes/core: Decrement uprobe count before the pages are unmapped uprobes/core: Make background page replacement logic account for rss_stat counters uprobes/core: Optimize probe hits with the help of a counter uprobes/core: Allocate XOL slots for uprobes use uprobes/core: Handle breakpoint and singlestep exceptions uprobes/core: Rename bkpt to swbp uprobes/core: Make order of function parameters consistent across functions uprobes/core: Make macro names consistent uprobes: Update copyright notices uprobes/core: Move insn to arch specific structure uprobes/core: Remove uprobe_opcode_sz uprobes/core: Make instruction tables volatile uprobes: Move to kernel/events/ uprobes/core: Clean up, refactor and improve the code ...
2012-05-24Merge branch 'tip/perf/urgent' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent Pull an ftrace ring-buffer fix from Steve Rostedt: * fix kernel crash when changing the size of the ring-buffer on boxes where possible_cpus != online_cpus. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-23ring-buffer: Check for valid buffer before changing sizeSteven Rostedt
On some machines the number of possible CPUS is not the same as the number of CPUs that is on the machine. Ftrace uses possible_cpus to update the tracing structures but the ring buffer only allocates per cpu buffers for online CPUs when they come up. When the wakeup tracer was enabled in such a case, the ftrace code enabled all possible cpu buffers, but the code in ring_buffer_resize() did not check to see if the buffer in question was allocated. Since boot up CPUs did not match possible CPUs it caused the following crash: BUG: unable to handle kernel NULL pointer dereference at 00000020 IP: [<c1097851>] ring_buffer_resize+0x16a/0x28d *pde = 00000000 Oops: 0000 [#1] PREEMPT SMP Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: [last unloaded: scsi_wait_scan] Pid: 1387, comm: bash Not tainted 3.4.0-test+ #13 /DG965MQ EIP: 0060:[<c1097851>] EFLAGS: 00010217 CPU: 0 EIP is at ring_buffer_resize+0x16a/0x28d EAX: f5a14340 EBX: f6026b80 ECX: 00000ff4 EDX: 00000ff3 ESI: 00000000 EDI: 00000002 EBP: f4275ecc ESP: f4275eb0 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 CR0: 80050033 CR2: 00000020 CR3: 34396000 CR4: 000007d0 DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 DR6: ffff0ff0 DR7: 00000400 Process bash (pid: 1387, ti=f4274000 task=f4380cb0 task.ti=f4274000) Stack: c109cf9a f6026b98 00000162 00160f68 00000006 00160f68 00000002 f4275ef0 c109d013 f4275ee8 c123b72a c1c0bf00 c1cc81dc 00000005 f4275f98 00000007 f4275f70 c109d0c7 7700000e 75656b61 00000070 f5e90900 f5c4e198 00000301 Call Trace: [<c109cf9a>] ? tracing_set_tracer+0x115/0x1e9 [<c109d013>] tracing_set_tracer+0x18e/0x1e9 [<c123b72a>] ? _copy_from_user+0x30/0x46 [<c109d0c7>] tracing_set_trace_write+0x59/0x7f [<c10ec01e>] ? fput+0x18/0x1c6 [<c11f8732>] ? security_file_permission+0x27/0x2b [<c10eaacd>] ? rw_verify_area+0xcf/0xf2 [<c10ec01e>] ? fput+0x18/0x1c6 [<c109d06e>] ? tracing_set_tracer+0x1e9/0x1e9 [<c10ead77>] vfs_write+0x8b/0xe3 [<c10ebead>] ? fget_light+0x30/0x81 [<c10eaf54>] sys_write+0x42/0x63 [<c1834fbf>] sysenter_do_call+0x12/0x28 This happens with the latency tracer as the ftrace code updates the saved max buffer via its cpumask and not with a global setting. Adding a check in ring_buffer_resize() to make sure the buffer being resized exists, fixes the problem. Cc: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-22Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial updates from Jiri Kosina: "As usual, it's mostly typo fixes, redundant code elimination and some documentation updates." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (57 commits) edac, mips: don't change code that has been removed in edac/mips tree xtensa: Change mail addresses of Hannes Weiner and Oskar Schirmer lib: Change mail address of Oskar Schirmer net: Change mail address of Oskar Schirmer arm/m68k: Change mail address of Sebastian Hess i2c: Change mail address of Oskar Schirmer net: Fix tcp_build_and_update_options comment in struct tcp_sock atomic64_32.h: fix parameter naming mismatch Kconfig: replace "--- help ---" with "---help---" c2port: fix bogus Kconfig "default no" edac: Fix spelling errors. qla1280: Remove redundant NULL check before release_firmware() call remoteproc: remove redundant NULL check before release_firmware() qla2xxx: Remove redundant NULL check before release_firmware() call. aic94xx: Get rid of redundant NULL check before release_firmware() call tehuti: delete redundant NULL check before release_firmware() qlogic: get rid of a redundant test for NULL before call to release_firmware() bna: remove redundant NULL test before release_firmware() tg3: remove redundant NULL test before release_firmware() call typhoon: get rid of redundant conditional before all to release_firmware() ...
2012-05-22Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf changes from Ingo Molnar: "Lots of changes: - (much) improved assembly annotation support in perf report, with jump visualization, searching, navigation, visual output improvements and more. - kernel support for AMD IBS PMU hardware features. Notably 'perf record -e cycles:p' and 'perf top -e cycles:p' should work without skid now, like PEBS does on the Intel side, because it takes advantage of IBS transparently. - the libtracevents library: it is the first step towards unifying tracing tooling and perf, and it also gives a tracing library for external tools like powertop to rely on. - infrastructure: various improvements and refactoring of the UI modules and related code - infrastructure: cleanup and simplification of the profiling targets code (--uid, --pid, --tid, --cpu, --all-cpus, etc.) - tons of robustness fixes all around - various ftrace updates: speedups, cleanups, robustness improvements. - typing 'make' in tools/ will now give you a menu of projects to build and a short help text to explain what each does. - ... and lots of other changes I forgot to list. The perf record make bzImage + perf report regression you reported should be fixed." * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (166 commits) tracing: Remove kernel_lock annotations tracing: Fix initial buffer_size_kb state ring-buffer: Merge separate resize loops perf evsel: Create events initially disabled -- again perf tools: Split term type into value type and term type perf hists: Fix callchain ip printf format perf target: Add uses_mmap field ftrace: Remove selecting FRAME_POINTER with FUNCTION_TRACER ftrace/x86: Have x86 ftrace use the ftrace_modify_all_code() ftrace: Make ftrace_modify_all_code() global for archs to use ftrace: Return record ip addr for ftrace_location() ftrace: Consolidate ftrace_location() and ftrace_text_reserved() ftrace: Speed up search by skipping pages by address ftrace: Remove extra helper functions ftrace: Sort all function addresses, not just per page tracing: change CPU ring buffer state from tracing_cpumask tracing: Check return value of tracing_dentry_percpu() ring-buffer: Reset head page before running self test ring-buffer: Add integrity check at end of iter read ring-buffer: Make addition of pages in ring buffer atomic ...
2012-05-22Merge branch 'for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
Pull workqueue changes from Tejun Heo: "Nothing exciting. Most are updates to debug stuff and related fixes. Two not-too-critical bugs are fixed - WARN_ON() triggering spurious during cpu offlining and unlikely lockdep related oops." * 'for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: lockdep: fix oops in processing workqueue workqueue: skip nr_running sanity check in worker_enter_idle() if trustee is active workqueue: Catch more locking problems with flush_work() workqueue: change BUG_ON() to WARN_ON() trace: Remove unused workqueue tracer
2012-05-21Merge branch 'tip/perf/core-2' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core
2012-05-21Merge branch 'perf/core' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core Fixes for perf/core: - Rename some perf_target methods to avoid double negation, from Namhyung Kim. - Revert change to use per task events with inheritance, from Namhyung Kim. - Events should start disabled till children starts running, from David Ahern. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-19tracing: Remove kernel_lock annotationsRichard Weinberger
The BKL is gone, these annotations are useless. Link: http://lkml.kernel.org/r/1320654202-4433-1-git-send-email-richard@nod.at Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-19tracing: Fix initial buffer_size_kb stateVaibhav Nagarnaik
Make sure that the state of buffer_size_kb is initialized correctly and returns actual size of the ring buffer. Link: http://lkml.kernel.org/r/1336066834-1673-1-git-send-email-vnagarnaik@google.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Laurent Chavey <chavey@google.com> Cc: Justin Teravest <teravest@google.com> Cc: David Sharp <dhsharp@google.com> Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-19ring-buffer: Merge separate resize loopsVaibhav Nagarnaik
There are 2 separate loops to resize cpu buffers that are online and offline. Merge them to make the code look better. Also change the name from update_completion to update_done to allow shorter lines. Link: http://lkml.kernel.org/r/1337372991-14783-1-git-send-email-vnagarnaik@google.com Cc: Laurent Chavey <chavey@google.com> Cc: Justin Teravest <teravest@google.com> Cc: David Sharp <dhsharp@google.com> Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-18Merge remote-tracking branch 'tip/perf/urgent' into perf/coreArnaldo Carvalho de Melo
Merge reason: We are going to queue up a dependent patch: "perf tools: Move parse event automated tests to separated object" That depends on: commit e7c72d8 perf tools: Add 'G' and 'H' modifiers to event parsing Conflicts: tools/perf/builtin-stat.c Conflicted with the recent 'perf_target' patches when checking the result of perf_evsel open routines to see if a retry is needed to cope with older kernels where the exclude guest/host perf_event_attr bits were not used. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-05-16ftrace: Remove selecting FRAME_POINTER with FUNCTION_TRACERSteven Rostedt
The function tracer will enable the -pg option with gcc, which requires that frame pointers. When FRAME_POINTER is defined in the kernel config it adds the gcc option -fno-omit-frame-pointer which causes some problems on some architectures. For those architectures, the FRAME_POINTER select was not set. When FUNCTION_TRACER was selected on these architectures that can not have -fno-omit-frame-pointer, the -pg option is still set. But when FRAME_POINTER is not selected, the kernel config would add the gcc option -fomit-frame-pointer. Adding this option is incompatible with -pg even on archs that do not need frame pointers with -pg. The answer to this was to just not add either -fno-omit-frame-pointer or -fomit-frame-pointer on these archs that want function tracing but do not set FRAME_POINTER. As it turns out, for archs that require frame pointers for function tracing, the same can be used. If gcc requires frame pointers with -pg, it will simply add it. The best thing to do is not select FRAME_POINTER when function tracing is selected, and let gcc add it if needed. Only add the -fno-omit-frame-pointer when something else selects FRAME_POINTER, but do not add -fomit-frame-pointer if function tracing is selected. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-16ftrace/x86: Have x86 ftrace use the ftrace_modify_all_code()Steven Rostedt
To remove duplicate code, have the ftrace arch_ftrace_update_code() use the generic ftrace_modify_all_code(). This requires that the default ftrace_replace_code() becomes a weak function so that an arch may override it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-16ftrace: Make ftrace_modify_all_code() global for archs to useSteven Rostedt
Rename __ftrace_modify_code() to ftrace_modify_all_code() and make it global for all archs to use. This will remove the duplication of code, as archs that can modify code without stop_machine() can use it directly outside of the stop_machine() call. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-16ftrace: Return record ip addr for ftrace_location()Steven Rostedt
ftrace_location() is passed an addr, and returns 1 if the addr is on a ftrace nop (or caller to ftrace_caller), and 0 otherwise. To let kprobes know if it should move a breakpoint or not, it must return the actual addr that is the start of the ftrace nop. This way a kprobe placed on the location of a ftrace nop, can instead be placed on the instruction after the nop. Even if the probe addr is on the second or later byte of the nop, it can simply be moved forward. Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-16ftrace: Consolidate ftrace_location() and ftrace_text_reserved()Steven Rostedt
Both ftrace_location() and ftrace_text_reserved() do basically the same thing. They search to see if an address is in the ftace table (contains an address that may change from nop to call ftrace_caller). The difference is that ftrace_location() searches a single address, but ftrace_text_reserved() searches a range. This also makes the ftrace_text_reserved() faster as it now uses a bsearch() instead of linearly searching all the addresses within a page. Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-16ftrace: Speed up search by skipping pages by addressSteven Rostedt
As all records in a page of the ftrace table are sorted, we can speed up the search algorithm by checking if the address to look for falls in between the first and last record ip on the page. This speeds up both the ftrace_location() and ftrace_text_reserved() algorithms, as it can skip full pages when the search address is not in them. Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-16ftrace: Remove extra helper functionsSteven Rostedt
The ftrace_record_ip() and ftrace_alloc_dyn_node() were from the time of the ftrace daemon. Although they were still used, they still make things a bit more complex than necessary. Move the code into the one function that uses it, and remove the helper functions. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-16ftrace: Sort all function addresses, not just per pageSteven Rostedt
Instead of just sorting the ip's of the functions per ftrace page, sort the entire list before adding them to the ftrace pages. This will allow the bsearch algorithm to be sped up as it can also sort by pages, not just records within a page. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-16tracing: change CPU ring buffer state from tracing_cpumaskVaibhav Nagarnaik
According to Documentation/trace/ftrace.txt: tracing_cpumask: This is a mask that lets the user only trace on specified CPUS. The format is a hex string representing the CPUS. The tracing_cpumask currently doesn't affect the tracing state of per-CPU ring buffers. This patch enables/disables CPU recording as its corresponding bit in tracing_cpumask is set/unset. Link: http://lkml.kernel.org/r/1336096792-25373-3-git-send-email-vnagarnaik@google.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Laurent Chavey <chavey@google.com> Cc: Justin Teravest <teravest@google.com> Cc: David Sharp <dhsharp@google.com> Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-16tracing: Check return value of tracing_dentry_percpu()Namhyung Kim
If tracing_dentry_percpu() failed, tracing_init_debugfs_percpu() will try to create each cpu directories on debugfs' root directory as d_percpu is NULL. Link: http://lkml.kernel.org/r/1335143517-2285-1-git-send-email-namhyung.kim@lge.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Namhyung Kim <namhyung.kim@lge.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-16ring-buffer: Reset head page before running self testSteven Rostedt
When the ring buffer does its consistency test on itself, it removes the head page, runs the tests, and then adds it back to what the "head_page" pointer was. But because the head_page pointer may lack behind the real head page (held by the link list pointer). The reset may be incorrect. Instead, if the head_page exists (it does not on first allocation) reset it back to the real head page before running the consistency tests. Then it will be put back to its original location after the tests are complete. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-16ring-buffer: Add integrity check at end of iter readSteven Rostedt
There use to be ring buffer integrity checks after updating the size of the ring buffer. But now that the ring buffer can modify the size while the system is running, the integrity checks were removed, as they require the ring buffer to be disabed to perform the check. Move the integrity check to the reading of the ring buffer via the iterator reads (the "trace" file). As reading via an iterator requires disabling the ring buffer, it is a perfect place to have it. If the ring buffer happens to be disabled when updating the size, we still perform the integrity check. Cc: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-16ring-buffer: Make addition of pages in ring buffer atomicVaibhav Nagarnaik
This patch adds the capability to add new pages to a ring buffer atomically while write operations are going on. This makes it possible to expand the ring buffer size without reinitializing the ring buffer. The new pages are attached between the head page and its previous page. Link: http://lkml.kernel.org/r/1336096792-25373-2-git-send-email-vnagarnaik@google.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Laurent Chavey <chavey@google.com> Cc: Justin Teravest <teravest@google.com> Cc: David Sharp <dhsharp@google.com> Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-16ring-buffer: Make removal of ring buffer pages atomicVaibhav Nagarnaik
This patch adds the capability to remove pages from a ring buffer without destroying any existing data in it. This is done by removing the pages after the tail page. This makes sure that first all the empty pages in the ring buffer are removed. If the head page is one in the list of pages to be removed, then the page after the removed ones is made the head page. This removes the oldest data from the ring buffer and keeps the latest data around to be read. To do this in a non-racey manner, tracing is stopped for a very short time while the pages to be removed are identified and unlinked from the ring buffer. The pages are freed after the tracing is restarted to minimize the time needed to stop tracing. The context in which the pages from the per-cpu ring buffer are removed runs on the respective CPU. This minimizes the events not traced to only NMI trace contexts. Link: http://lkml.kernel.org/r/1336096792-25373-1-git-send-email-vnagarnaik@google.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Laurent Chavey <chavey@google.com> Cc: Justin Teravest <teravest@google.com> Cc: David Sharp <dhsharp@google.com> Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-16tracing: Clean up tracing_mark_write()Steven Rostedt
On gcc 4.5 the function tracing_mark_write() would give a warning of page2 being uninitialized. This is due to a bug in gcc because the logic prevents page2 from being used uninitialized, and gcc 4.6+ does not complain (correctly). Instead of adding a "unitialized" around page2, which could show a bug later on, I combined page1 and page2 into an array map_pages[]. This binds the two and the two are modified according to nr_pages (what gcc 4.5 seems to ignore). This no longer gives a warning with gcc 4.5 nor with gcc 4.6. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-14Merge branch 'perf/uprobes' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/uprobes
2012-05-10tracing: Do not enable function event with enableSteven Rostedt
With the adding of function tracing event to perf, it caused a side effect that produces the following warning when enabling all events in ftrace: # echo 1 > /sys/kernel/debug/tracing/events/enable [console] event trace: Could not enable event function This is because when enabling all events via the debugfs system it ignores events that do not have a ->reg() function assigned. This was to skip over the ftrace internal events (as they are not TRACE_EVENTs). But as the ftrace function event now has a ->reg() function attached to it for use with perf, it is no longer ignored. Worse yet, this ->reg() function is being called when it should not be. It returns an error and causes the above warning to be printed. By adding a new event_call flag (TRACE_EVENT_FL_IGNORE_ENABLE) and have all ftrace internel event structures have it set, setting the events/enable will no longe try to incorrectly enable the function event and does not warn. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-08tracing: Remove ftrace_disable/enable_cpu()Steven Rostedt
The ftrace_disable_cpu() and ftrace_enable_cpu() functions were needed back before the ring buffer was lockless. Now that the ring buffer is lockless (and has been for some time), these functions serve no purpose, and unnecessarily slow down operations of the tracer. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-08tracing: Use seq_*_private interface for some seq filesJiri Olsa
It's appropriate to use __seq_open_private interface to open some of trace seq files, because it covers all steps we are duplicating in tracing code - zallocating the iterator and setting it as seq_file's private. Using this for following files: trace available_filter_functions enabled_functions Link: http://lkml.kernel.org/r/1335342219-2782-5-git-send-email-jolsa@redhat.com Signed-off-by: Jiri Olsa <jolsa@redhat.com> [ Fixed warnings for: kernel/trace/trace.c: In function '__tracing_open': kernel/trace/trace.c:2418:11: warning: unused variable 'ret' [-Wunused-variable] kernel/trace/trace.c:2417:19: warning: unused variable 'm' [-Wunused-variable] ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-07tracing: Provide trace events interface for uprobesSrikar Dronamraju
Implements trace_event support for uprobes. In its current form it can be used to put probes at a specified offset in a file and dump the required registers when the code flow reaches the probed address. The following example shows how to dump the instruction pointer and %ax a register at the probed text address. Here we are trying to probe zfree in /bin/zsh: # cd /sys/kernel/debug/tracing/ # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh # objdump -T /bin/zsh | grep -w zfree 0000000000446420 g DF .text 0000000000000012 Base zfree # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events # cat uprobe_events p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 # echo 1 > events/uprobes/enable # sleep 20 # echo 0 > events/uprobes/enable # cat trace # tracer: nop # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Linux-mm <linux-mm@kvack.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120411103043.GB29437@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-07tracing: Extract out common code for kprobes/uprobes trace eventsSrikar Dronamraju
Move parts of trace_kprobe.c that can be shared with upcoming trace_uprobe.c. Common code to kernel/trace/trace_probe.h and kernel/trace/trace_probe.c. There are no functional changes. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Linux-mm <linux-mm@kvack.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120409091144.8343.76218.sendpatchset@srdronam.in.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-07tracing: Modify is_delete, is_return from int to boolSrikar Dronamraju
is_delete and is_return can take utmost 2 values and are better of being a boolean than a int. There are no functional changes. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com> Cc: Linux-mm <linux-mm@kvack.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120409091133.8343.65289.sendpatchset@srdronam.in.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-04-23ring-buffer: Add per_cpu ring buffer control filesVaibhav Nagarnaik
Add a debugfs entry under per_cpu/ folder for each cpu called buffer_size_kb to control the ring buffer size for each CPU independently. If the global file buffer_size_kb is used to set size, the individual ring buffers will be adjusted to the given size. The buffer_size_kb will report the common size to maintain backward compatibility. If the buffer_size_kb file under the per_cpu/ directory is used to change buffer size for a specific CPU, only the size of the respective ring buffer is updated. When tracing/buffer_size_kb is read, it reports 'X' to indicate that sizes of per_cpu ring buffers are not equivalent. Link: http://lkml.kernel.org/r/1328212844-11889-1-git-send-email-vnagarnaik@google.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Michael Rubin <mrubin@google.com> Cc: David Sharp <dhsharp@google.com> Cc: Justin Teravest <teravest@google.com> Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-04-23tracing: Remove an unneeded check in trace_seq_buffer()Dan Carpenter
memcpy() returns a pointer to "bug". Hopefully, it's not NULL here or we would already have Oopsed. Link: http://lkml.kernel.org/r/20120420063145.GA22649@elgon.mountain Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-04-23tracing: Add percpu buffers for trace_printk()Steven Rostedt
Currently, trace_printk() uses a single buffer to write into to calculate the size and format needed to save the trace. To do this safely in an SMP environment, a spin_lock() is taken to only allow one writer at a time to the buffer. But this could also affect what is being traced, and add synchronization that would not be there otherwise. Ideally, using percpu buffers would be useful, but since trace_printk() is only used in development, having per cpu buffers for something never used is a waste of space. Thus, the use of the trace_bprintk() format section is changed to be used for static fmts as well as dynamic ones. Then at boot up, we can check if the section that holds the trace_printk formats is non-empty, and if it does contain something, then we know a trace_printk() has been added to the kernel. At this time the trace_printk per cpu buffers are allocated. A check is also done at module load time in case a module is added that contains a trace_printk(). Once the buffers are allocated, they are never freed. If you use a trace_printk() then you should know what you are doing. A buffer is made for each type of context: normal softirq irq nmi The context is checked and the appropriate buffer is used. This allows for totally lockless usage of trace_printk(), and they no longer even disable interrupts. Requested-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-04-19tracing: Fix stacktrace of latency tracers (irqsoff and friends)Steven Rostedt
While debugging a latency with someone on IRC (mirage335) on #linux-rt (OFTC), we discovered that the stacktrace output of the latency tracers (preemptirqsoff) was empty. This bug was caused by the creation of the dynamic length stack trace again (like commit 12b5da3 "tracing: Fix ent_size in trace output" was). This bug is caused by the latency tracers requiring the next event to determine the time between the current event and the next. But by grabbing the next event, the iter->ent_size is set to the next event instead of the current one. As the stacktrace event is the last event, this makes the ent_size zero and causes nothing to be printed for the stack trace. The dynamic stacktrace uses the ent_size to determine how much of the stack can be printed. The ent_size of zero means no stack. The simple fix is to save the iter->ent_size before finding the next event. Note, mirage335 asked to remain anonymous from LKML and git, so I will not add the Reported-by and Tested-by tags, even though he did report the issue and tested the fix. Cc: stable@vger.kernel.org # 3.1+ Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-04-18Fix "the the" in various KconfigMasanari Iida
Fix typo "the the" in various Kconfig. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-04-16tracing: Fix regression with tracing_onSteven Rostedt
The change to make tracing_on affect only the ftrace ring buffer, caused a bug where it wont affect any ring buffer. The problem was that the buffer of the trace_array was passed to the write function and not the trace array itself. The trace_array can change the buffer when running a latency tracer. If this happens, then the buffer being disabled may not be the buffer currently used by ftrace. This will cause the tracing_on file to become useless. The simple fix is to pass the trace_array to the write function instead of the buffer. Then the actual buffer may be changed. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-04-13tracing: Fix build breakage without CONFIG_PERF_EVENTS (again)Mark Brown
Today's -next fails to link for me: kernel/built-in.o:(.data+0x178e50): undefined reference to `perf_ftrace_event_register' It looks like multiple fixes have been merged for the issue fixed by commit fa73dc9 (tracing: Fix build breakage without CONFIG_PERF_EVENTS) though I can't identify the other changes that have gone in at the minute, it's possible that the changes which caused the breakage fixed by the previous commit got dropped but the fix made it in. Link: http://lkml.kernel.org/r/1334307179-21255-1-git-send-email-broonie@opensource.wolfsonmicro.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-04-11trace: Remove unused workqueue tracerStephen Boyd
This tracer was temporarily removed in 6416669 (workqueue: temporarily remove workqueue tracing, 2010-06-29) but never reinstated after concurrency managed workqueues were completed. For almost two years it hasn't been compilable so it seems nobody is using it. Delete it. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2012-04-05Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds
Merge batch of fixes from Andrew Morton: "The simple_open() cleanup was held back while I wanted for laggards to merge things. I still need to send a few checkpoint/restore patches. I've been wobbly about merging them because I'm wobbly about the overall prospects for success of the project. But after speaking with Pavel at the LSF conference, it sounds like they're further toward completion than I feared - apparently davem is at the "has stopped complaining" stage regarding the net changes. So I need to go back and re-review those patchs and their (lengthy) discussion." * emailed from Andrew Morton <akpm@linux-foundation.org>: (16 patches) memcg swap: use mem_cgroup_uncharge_swap fix backlight: add driver for DA9052/53 PMIC v1 C6X: use set_current_blocked() and block_sigmask() MAINTAINERS: add entry for sparse checker MAINTAINERS: fix REMOTEPROC F: typo alpha: use set_current_blocked() and block_sigmask() simple_open: automatically convert to simple_open() scripts/coccinelle/api/simple_open.cocci: semantic patch for simple_open() libfs: add simple_open() hugetlbfs: remove unregister_filesystem() when initializing module drivers/rtc/rtc-88pm860x.c: fix rtc irq enable callback fs/xattr.c:setxattr(): improve handling of allocation failures fs/xattr.c:listxattr(): fall back to vmalloc() if kmalloc() failed fs/xattr.c: suppress page allocation failure warnings from sys_listxattr() sysrq: use SEND_SIG_FORCED instead of force_sig() proc: fix mount -t proc -o AAA
2012-04-05simple_open: automatically convert to simple_open()Stephen Boyd
Many users of debugfs copy the implementation of default_open() when they want to support a custom read/write function op. This leads to a proliferation of the default_open() implementation across the entire tree. Now that the common implementation has been consolidated into libfs we can replace all the users of this function with simple_open(). This replacement was done with the following semantic patch: <smpl> @ open @ identifier open_f != simple_open; identifier i, f; @@ -int open_f(struct inode *i, struct file *f) -{ ( -if (i->i_private) -f->private_data = i->i_private; | -f->private_data = i->i_private; ) -return 0; -} @ has_open depends on open @ identifier fops; identifier open.open_f; @@ struct file_operations fops = { ... -.open = open_f, +.open = simple_open, ... }; </smpl> [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-27tracing: Fix ent_size in trace outputSteven Rostedt
When reading the trace file, the records of each of the per_cpu buffers are examined to find the next event to print out. At the point of looking at the event, the size of the event is recorded. But if the first event is chosen, the other events in the other CPU buffers will reset the event size that is stored in the iterator descriptor, causing the event size passed to the output functions to be incorrect. In most cases this is not a problem, but for the case of stack traces, it is. With the change to the stack tracing to record a dynamic number of back traces, the output depends on the size of the entry instead of the fixed 8 back traces. When the entry size is not correct, the back traces would not be fully printed. Note, reading from the per-cpu trace files were not affected. Reported-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>